Amino esters of (2, 3 or 4) pyridyl carbamic acid



United States Patent ce 3,376,307

Patented Apr. 2, 1968 Example 1.-O-3 pyridylmethyl-N-l-pyridylcarbamate 3,376,307 0 AMINO ESTERS 0F (2,3 or 4) PYRIDYL CARBAMIC ACID NH-C-OCH: Seymour Hyden, Spring Valley, and Godfrey Wilbert, 5

Carmel, N.Y., assignors to Nepera Chemical Co., Inc. No Drawing. Filed Oct. 29, 1964, Ser. No. 407,575 N/ N 5 Claims- (C 260-2943) A solution of 5 grams of pyridine-3-isocyanate in about 50 cc. of benzene is added to a solution of 5 grams of pyridine-3-carbinol in 50 cc. of benzene at 0 C. and the ABSTRACT OF THE DISCLOSURE mixture is warmed slowly to an ambient temperature of A class of urethane derivatives of the formula: 20 to 30 C. and allowed to stand for 24 hours. Hexane is added to the mixture; the precipitated O-3-pyiri'dyl- R1 R2 methyl-N-B-pyridylcarbamate then being collected by H filtration and the initial product is recrystallized from NHU-O R3 benzene-hexane to yield 5.7 grams of a white solid, M.P.

\ 148-149 C. The infra-red spectrum features a band at N 1720 CUR-1. (0:0).

wherein R R and R :are as defined below. These com- Example 2 -O'(N methy1 3'plp pounds are useful as herbicides. pyrldylcagbamate NH-ii-O This invention relates to a composition of matter and I more particularly to novel urethane derivatives having 25 N N the formula. I

XX 2 A solution of 1.2 grams of N-methyl-3-piperidinol in L H about 50 cc. of chloroform is added to a solution of 1.2 3 grams of pyridine-3-isocyanate in 50 cc. of chloroform and the mixture is warmed on the steam bath for 30 minutes. The chloroform is removed by distillation to afford eidu'visc liui as i'- -0 ol' wherein R may be hydrogen, lower alkyl such as methyl, g zf i i g 1 fggffgigg i g g ethyl mp Y1 and the hke; halogen F as chlom or carbamate is recrystallized from benzene-hexane to yield bromo; nitro; aryl such as phenyl; substituted aryl such 12 grams Of aWhite solid 0 0 The infnkmd as p-chlorophenyl, 3,4-dichlorophenyl, p-methoxyphenyl; Spectrum features a band 1710 (C=O) or a he-terocyclic radical such as furyl, pyridyl and the like, R may be hydrogen, lower alkyl; aryl such as phenyl; EXflmple )-PY Y Y 'PY y alkenyl such as vinyl; aralkyl such as tolyl; halogen; halo- 40 alkyl; alkoyl; and aroyl such as benzoyl, and R is a heterocyclic radical such as furyl, pyridyl, pyaimidyl,

H imidazolyl, quinolyl, isoquinolyl, dibenzofuryl; or a \N heterocyclic radical substituted with 1, 2 or 3 lower alkyl groups; halo; or phenyl. \N ful l g l lde S j l d are useful as msecucldes Asolution of 1 gram of pyridine-Z-ethanol in St) cc. of The compounds of this invention are prepared by react- Penzcne added to a solutlon of 1 gram; of fi inc a pyridine isocyanate of the formula: isocyanate in cc. of benzene and the mixture s heated 50 on the steam bath for 30 minutes. The reaction is cooled to an ambient temperature of 20 to 30 C. and upon addition of hexane, 0-2-(5)-pyridylethyl-N3-pyridyl- (Noon carbamate precipitates. The carbamate is recrystallized from benzene-hexane to yield 1.7 grams of a white solid, M.P. 121123 C. The infra-red spectrum features a band at 1710 cmf (0:0). with an alcohol of t formula! Example 4.O-3-pyridyl-N-3-pyridy1carbamate R OH wherein R R and R are as defined and n is an integer NHCO- of 1 to 3. The reaction is effected by contacting the starting materials at a temperature range of (P-80 C. in a J \N solvent system consisting of benzene, ether, chloroform and the like. The reaction product is recovered by addition A suspension of 1 gramof 3-hydroxypyridine in 50 cc. of hexane to the reaction mixture and collected by of benzene is added to a solution of 1 gram of pyridinefiltration. 3-isocyanate in 50 cc. of benzene and the mixture is heated The starting isocyanates are prepared according to the on the steam bath for 30 minutes. The reaction mixture process described in eopending application Pyridine Isois cooled in an ice Water bath and the O-3-pyridyl-N-3- cyanates, Ser. No. 407,574, filed Oct. 29, 1964, now yridylcarbamate that precipitates is collected by filtration. abandoned. The carbamate is recrystallized from benzene to yield 1.6

The following examples are included in order further grams of a white solid, M.P. l4l8150.5 C. The infra-red to illustrate the invention. spectrum features a band at 1735 cmr (0:0).

It is understood that the foregoing detailed description piperidyl, pyridyl lower alkyl, piperidyl lower alkyl, or is given merely by way of illustration and that many va'ria- N-lower .alkyl piperidyl. tions may be made therein without departing from the 2. 0-3-pyridylmethylN-3-pyridylcarbamate. spirit of our invention. 3. O-(N-menhyl-3-piperidyl) -N-3-pyridylcarbamate.

Having described our invention, what we desire to 5 4. O-Z-(fl)-pyridylethyl-N-3-pyridylcarbamate. secure by Letters Patent is: 5. O-3-pyridyl-N-3-pyridy1carban1ate.

1. A compound of the formula:

References Cited O UNITED STATES PATENTS r fir 10 2,772,276 11/1956 Cusic 260294.3 2,914,533 11/1959 Clinton 260-294.3 \N/ 3,249,619 5/1966 Johnston 260-295 wherein R is hydrogen, phenyl, or lower alkyl, R is 15 JOHN RANDOLPH P r imary Examiner hydrogen, P y or lower alkyl, and 3 is Py y A. D. SPEVACK, Assistant Examiner. 

